Pentile OLEDs: introduction and market status

Article last updated on: Feb 10, 2019

PenTile RGBG matrix technology explained

Samsung's Pentile matrix technology is a sub-pixel design architecture family. The basic PenTile structure is the RGBG matrix. In RGBG PenTile displays there are only two subpixels per pixel, with twice as many green pixels than red and blue ones. You can see a PenTile matrix vs a Real-Stripe one on the images below (the PenTile is on the right):

The Pentile technology was commercialized by Clairvoyante. In March 2008, Samsung bought the company's PenTile related IP and technology, and formed a new company called Nuovoyance to continue development of this display technology. Here's an image from Nuovoyance showing Pentile vs RGB matrix (which they call a 'legacy' matrix):

PenTile relies on the human eye design - if you reduce the number of blue subpixels, you barely reduce the image quality. There are other advantages to PenTile displays (for example longer liftime, which will be explained below). But even Samsung admits that a real-stripe RGB matrix is better than Pentile, for example here's some marketing image from Samsung showing how a non-Pentile display (the Super AMOLED Plus) is better than the pentile Super AMOLED:

Some people indeed do not like PenTile displays. Mostly it seems because there is a visible pattern when you look at the display up close. Your eyes get used to this pattern quickly though, and the higher resolution the display is, the less visible the pattern is. Modern PenTile OLED displays reach very high pixel densities that make it virtually impossible to notice the patern.

Samsung's AMOLED and Super AMOLED displays

Samsung uses PenTile technology in virtually all of their Super AMOLED displays, which are used in most of the company's smartphones - including the Galaxy S7 and S7 edge.

Diamond Pixel Pentile

Samsung's latest Super AMOLED displays adopt a new subpixel arrangement called Diamond Pixel. The first phone to use this pentile type was the Galaxy S4 (later phones adopted a slightly different Diamond pattern). In a Diamond Pixel display, there are twice as many green subpixels as there are blue and red ones, and the green subpixels are oval and small while the red and blue ones are diamond-shaped and larger (the blue subpixel is slightly larger than the red one). The diamond shapes were chosen to maximize the sub-pixel packing and achieve the highest possible PPI. The greens are oval because they are squeezed between the larger red and blue ones.

Tianma also demonstrated several flexible OLEDs in many configurations which we will list below. Almost all of the panels were based on the same basic display - a flexible 5.99" WQHD 1440x2280 (537.5 PPI) AMOLED produced on a polyimide substrate. Tianma showed this panel in a regular design, and also in a notch-type design.

The 2014 Galaxy S5 introduced a different Diamond Pixel scheme which Samsung uses till today. DisplayMate tested the Apple iPhone X and it turns out that Apple's OLED, even though it is produced by Samsung Display, uses a slightly different Diamond Pixels - the fill factor of Apple's display is higher than in the Galaxy phones. You can see the two different displays in the macro photos above (courtesy of Display Mate). The iPhone X OLED is on the left, while the right shows the Galaxy OLED.

Samsung started shipping its Galaxy S8 and Galaxy S8+ phones in Korea, and some of the first customers are complaining that the display have a reddish tint - which did not go away even after correcting the color display settings. This issues was quickly labeled as "Red Gate"... will Samsung face a new crisis?

Samsung itself says that there are no quality issues - and that the problem can be adjusted. Customers are welcome to replace their device, though, at service centers in Korea.

Samsung Display developed a new high-resolution OLED display, specifically for VR applications. The 5.5" panel, on display at SID DisplayWeek, sported a 3840x2160 resolution - or 806 PPI. The panel offered a brightness of 350 nits and a color gamut of 97% adobe RGB.

eMagin, the OLED microdisplay maker, reported their financial results for Q3 2015. Revenues were $5.4 million - down from $7 million in Q2 2015 due to a decrease in both product sales and R&D contract revenue. Net loss was $2.2 million, and eMagin currently has $5.1 million in cash and equivalents.

The OLED Association reports that Shanghai Tianma demonstrated a new 5.5" Full-HD (400 PPI) AMOLED prototype. This is the highest-resolution display ever shown by the Chinese display maker, and reportedly they have adopted a subpixel scheme not unlike Samsung's Pentile technology. To achieve the high resolution, Tianma developed a dual-FMM technology in-house.

DisplayMate posted yet another interesting display shoot-out, this one testing Samsung's new QHD (2560x1600) Super AMOLED displays used in the upcoming Galaxy Tab S (8.4 and 10.5) tablets. As these displays are very similar to the GS5 display, it's not surprising that DisplayMate found those tablets to offer the best performing displays ever. This is yet another testimony to how great OLED displays are - and the rate of improvement in OLEDs is very rapid.

As DisplayMate found out, the Galaxy Tab S establishes new records for best Tablet display performance in: Highest Color Accuracy, Infinite Contrast Ratio, Lowest Screen Reflectance, and smallest Brightness Variation with Viewing Angle. These are also the highest resolution tablets at QHD.

When Samsung first released the GS5, we thought the 5.1" FHD Super AMOLED display is pretty similar to the 4.99" FHD one used in the GS4. But DisplayMate found out that this is a much superior display in many aspects, one of them being that it is 27% more efficient.

GS5 subpixels

GS4 subpixels

Samsung told DisplayMate that the improvement mostly came from more efficient OLED materials. They also incorporated new display electronics and optics and that helped as well. But now Chipworks posted a teardown of the GS5, and they published a macro image of the display's sub pixels. It turns out that it's a different architecture than the GS4, and this may explains some of the performance boost, too.

Visionox developed a new RGB pixel arrangement for OLED technologies that allowed them to reach 570 PPI. The company refers to this new technology as Z-Type arrangement and it includes 3 sub-pixels (RGB) per pixel (unlike Samsung's Pentile displays). The sub-pixels are densely packed (the aperture ratio seems very high) in a way that does not suffer from jagged edges.

Visionox told me that they cannot yet say when such displays can be commercialized, as there are still manufacturing challenges to overcome. In the meanwhile the company applied for both Chinese and international patents.

The Oculus Rift is a VR HMD being developed by Oculus VR. The high profile company raised $16 million (partly by crowdfunding) and already offer "development kits" HMDs. Their consumer version (Oculus CV) will hopefully be released in 2014 and will feature improved components, for example a Full-HD display. The current versions use LCD displays (7" in size, although early prototypes used 5.6").

Oculus VR development edition

Yesterday, at Oculus' development forums, a new discussion suggested that Oculus aims to adopt an OLED display in the Oculus CV. They quote Oculus CEO Brandon Iribe as saying that the need a much faster display than the current one, and that OLED was the technology that could achieve that.